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Stack #40838
Question | Answer |
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Which is the best statement of the principle of original horizonality? | sediments are deposited as horizontal layers |
An undeformed sedimentary layer is _____ than the layer above and _____ than the layer below. | OLDER then the layer above and YOUNGER than the layer below |
The principle of superposition states that | undistrubuted sedimentary layers get progessively younger from bottom to top. |
The most common fossils in rocks of the past 500 million years are | Invertebrae Shells |
Fossils are most common in which rock types? | Sedimentary |
Which is an unconformity? | A gap in the geologic record |
Which of the following is the smallest division of geologic time? | Epochs |
When did the Mesozoic era begin? | 250 million years ago |
Radiometric dating is least useful for dating ______________ rocks | Sedimentary |
Radiometric dating is possible if a rock contains measurable amounts of | both daughter and parent atoms |
Which of the following statements is false? | Weathering and erosion are more important in the oceans than on continents |
If you were to start from the east coast of North America and descend into the Atlantic Ocean, you would travel along the | Continental shelf then the continental slope then the continental rise. |
In which of the following locations would you most likely find outcrops of basalt on the ocean floor? | on the flank of a rift valley |
A traverse from North America across the Atlantic Ocean to Continental Europe would reveal that the ocean floor | is approximately symmetric about the Mid-Atlantic Ridge |
Where is the ocean floor deepest? | about 30 km deep |
Graded beds of sand, silt, and mud deposited on submarine fans are called | turbidites |
Where does most volcanic activity on the seafloor take place? | Mid-ocean ridges |
Which of the following is an active continental margin? | the west coast of South America |
Which of the following best describes pelagic sediments? | deposited far from continental margins, fine grained, settle slowly on seafloor, ALL OF ABOVE!! |
Which of the following currents erodes deposit fine-grained sediments on the continental slope and rise? | turbidity currents |
The earths earliest atmosphere most likely did not contain any | unattached oxygen |
Life's orgin on earth is believe to have been depend on the prescence of | carbon based chemicals, water, energy, ALL OF THE ABOVE |
The first forms on life on Earth | were prokaryotes |
The first evidence of fossils that appear to be the remains of living organisms are found in rocks | 3.8 billion years old |
Unicellular organisms with a membrane bound nucleus that appeared some 2.0 billion years ago are referred to as | Eukaryotes (protistans) |
The ___________ refers to the sudden appearance of a large number of complex animals at the beginning of the Paleozoic Era | Cambrian Explosion |
Which statement is correct? | Anaerobic respiration preceded aerobic respiration |
The Permian extinction | resulted in the extinction of over 90% of marine life and half of the life on land. |
According to the 'Snowball Earth' hypothesis | ALL OF THE ABOVE |
The K-T extinction | resulted in the extinction of the dinosaurs |
What does the elastic rebound theory describe? | the build-up and release of stress during an earthquake |
Point A, where slip iniated during the earthquake, is called the | focus |
Point B is called the earthquake (at the surface) | epicenter |
What is the maximum amount of slip on a fault during an earthquake? | about 10 meters |
Which statement regarding aftershocks is true? | The # and size of aftershocks both decrease with time. |
Which type of seismic waves arrive at a seismograph first? | P-waves |
Which lists the order in which seismic waves arrive at a seismograph station? | p waves> s waves> surface waves |
Which seismic waves are the slowest? | surface waves |
An earthquake's Richter Magnitude is based on | the amount of ground movement caused by seismic waves |
The energy released during a magnitude 8 earthquake is approximately ______ times large than the energy released during a magnitude 6 earthquake | 1000 times |
What kind of faulting is most likely to cause tsunamis? | thrust mega-thrust |
Shallow earthquakes less then 20 km deep, are associated with | convergent, divergent, and transform fault boundries |
What type of faulting would be least likely to occur along the mid-atlantic ridge? | reverse faulting |
which of the following recent earthquakes killed the most people? | the 2001 Gujarat earthquake, India |
Earthquakes that orginate at depths greater then 100 km are associated with _______ plate boundries | convergent |
Which of the following statements about tsumanis is false? | tsunamis are producted by tidal forces, which is why they are also called tidal waves |
How fast do tsunamis travel across the ocean? | up to 800 km per hour |
Which of the following statements is the most accurate? | seismic risks can be reduced, but seismic hazards cannot. |
Which of the following regions has the greatest seismic hazards? | western US |
Tsuamis can be generated by | undersea landslides, undersea earthquakes, the eruption of an oceanic volcano, ALL OF ABOVE |
What volcano represents a major hazard to the cities of Seattle and Tacoma in Washington State? | Mount Rainier |
Where do most basaltic magmas originate? | in the earth asthenosphere |
Which of the following statements about lava is true? | high temperate lavas are less viscous then low temperature lavas |
Which of the following lavas will travel downhill slowest? | rhyolite |
Solidified fragments of volcanic material ejected into the air are called | pyroclasts |
What type of volcano has the largest and most violent eruptions? | resurgent calderas |
Huge mudflows made up of wet volcani debris are called | lahars |
Which of the following gases is the main constitent of volcanic gas? | sulfur dioxide |
Most of the world's active volcanos are located around the edge of which ocean? | Pacific Ocean |
The Cascade Volcanoes are associated with a | convergent plate margin |
Over the past 2000 years, which of the following volcanic hazard has caused the most fatalities? | pyroclastic flows |